The invention concerns a process and apparatus for dyeing textile goods.
A process and an apparatus of this type for the dyeing of widths of textile goods are known from U.S. Pat. No. 3,969,780. Here, the foam is uniformly applied over the width of the goods; it penetrates into the material, and the dye contained in the foam is fixed in the conventional manner. The metering of the dye is effected in that the applied foam layer is doctored off at a height that is constant transversely of the width of the fabric. This height may be adjusted with great accuracy so that the metering of the dye applied per surface unit of the fabric is highly accurate. Since, however, the application is effected uniformly over the width of the fabric, only single color dyeing is possible.
It has also been proposed in principle to obtain patterned dyeing of a width of fabric by the patterned application of different dye foams (DE-AS 22 14 377).
A machine for the patterning of wallpaper is known from U.S. Pat. No. 596,905, wherein a roll rotates in a dye trough extending transversely over and above the width of material. The roll is partially immersed in the trough during its rotation. A doctor blade is applied against a downwardly traveling side of the roll. The doctor blade rakes off the layer of liquid entrained on the surface of the roll, which then flows over the doctor blade obliquely inclined to the fabric and drops in a veil from the lower edge of the blade onto the fabric. In the trough, lanes are provided by means of partitions extending parallel to the direction of travel of the fabric and reaching the roll. The partitions are engaging a plurality of grooves in the roll. Each lane is associated with a feeder device, whereby different dye liquids may be fed into the individual lanes. The liquids are passed separately onto the blade but are intermixed in a predetermined manner during their further travel to the fabric. This device is not suitable for the transfer of foam; it is not possible to produce definite layers of foam in the individual lanes with such known apparatus.
In the process according to DE-AS No. 22 14 377 the means promoting the decomposition of the foam is either added immediately to the foam or it is subsequently sprayed onto the foam, or else applied flat in another manner to the foam. In both cases, the relatively small amount of the liquid containing the patterning agent is contacting initially the outer fibers, i.e., those located on the side of the application of the foam and these therefore necessarily are receiving a higher concentration of chemicals than fibers located at a greater depth, which are reached by the liquid only after it has given up a portion of its chemicals to the outer fibers. In this manner, a distribution that is uniform over the surface of the width of the fabric is obtained during the application of the patterning substance in the form of a foam, but not uniform over the depth of the fabric. In certain cases this may represent a disadvantage. The subsequent working of the foam or of the liquid formed by it into the fabric by suction, blowing or squeezing cannot correct this condition with the slight amount of the liquid offered, as shown by experimentation.
It is the object of the invention to provide a process and an apparatus whereby pattern dyeing of this type may actually be effected.
Another object is to enable layers of foam of definite preselected height to be formed and then applied to a textile.
A further object is to promote a greater degree of uniformity to dye application in the direction of the depth of a material being dyed.